Passive electrical components with inorganic dielectric coating layer

ABSTRACT

A passive electrical component includes an inorganic dielectric coating layer laser applied to a conductor layer.

REFERENCE TO RELATED APPLICATIONS

The present disclosure is a continuation application of U.S. patent application Ser. No. 12/344570, filed Dec. 28, 2008.

BACKGROUND

The present disclosure relates to passive electrical components.

The advent of relatively high temperature semiconductor devices, such as silicon-on-sapphire (SOS) and wide-band gap (WBG) semiconductors, has produced devices which can operate at high temperatures from 200° C. to 300° C. base plate temperatures. In comparison, silicon based devices have maximum base plate temperatures of 85° C. to 125° C.

However, not all passive electrical components used with the high temperature semiconductor devices have been optimized for such high temperatures. Current passive electrical components provide significantly reduced efficiency in a 300° C. environment.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features will become apparent to those skilled in the art from the following detailed description of the disclosed non-limiting embodiment. The drawings that accompany the detailed description can be briefly described as follows:

FIG. 1 is a sectional view through a passive electrical component;

FIG. 2A schematically illustrates a coupon testing proof of concept having a multiple of capacitor areas;

FIG. 2B illustrates the scale of the capacitor area;

FIGS. 3A-3N illustrate particular coupons with an Average Capacitance/Breakdown Voltage for each capacitor area C on the coupon.

FIG. 4 is a graph which defines a capacitance per area based in part on the material combination of a inorganic dielectric coating layer;

FIG. 5 is a sectional view through another passive electrical component;

FIG. 6 is a sectional view through another passive electrical component;

FIG. 7 is a sectional view through another passive electrical component; and

FIG. 8 is a schematic view of a passive electrical component mounted to a substrate which is a case for other electronic components.

DETAILED DESCRIPTION

FIG. 1 schematically illustrates a passive electrical component 10A which in this disclosed non-limiting embodiment is illustrated as a capacitor 12. The capacitor 12 includes a multiple of conductor layers 14 with an inorganic dielectric coating layer 16 therebetween. When a voltage potential difference occurs between the conductor layers 14, an electric field occurs in the inorganic dielectric coating layer 16 as generally understood. The capacitor 12 may include a multiple of layers, here illustrated with three inorganic dielectric coating layers 16 and alternating connected conductor layers 14.

The capacitor 12 may be formed on a substrate 18. The substrate 18 may be a conductive substrate such as aluminum or a non-conductive substrate deposited with a conductive layer such as silicon carbide (SiC) layered with aluminum. In one non-limiting embodiment, the aluminum may be polished to provide a surface roughness of approximately 20 nm to 85 nm.

The conductor layers 14 may be formed of, for example, aluminum, nickel, copper, gold or other conductive inorganic material or combination of materials. Various aspects of the present disclosure are described with reference to a multiple of inorganic dielectric coating layers 16 and alternating connected conductor layers 14 formed adjacent or on the substrate or upon another layer. As will be appreciated by those of skill in the art, references to a layer formed on or adjacent another layer or substrate contemplates that additional other layers may intervene.

The inorganic dielectric coating layer 16 may be formed of, for example, halfnium oxide, silicone dioxide, silicon nitrides, fused aluminum oxide, Al_(0.66)Hf_(0.33)O₃, Al_(0.8)Hf_(0.2)O₃, Al_(0.5)Y_(0.5)O₃, or other inorganic materials or combination of inorganic materials. In one non-limiting embodiment, the inorganic dielectric coating layer 16 may be deposited to a thickness from approximately 0.6 microns to 10 microns.

The inorganic dielectric coating layer 16 may be applied through a pulsed laser deposition (PLD) process such as that provided by Blue Wave Semiconductors, Inc. of Columbia, Md. USA. The PLD process facilitates multiple combinations of metal-oxides and nitrides on SiC, Si, AN, Al, Cu, Ni or any other suitable flat surface. A multilayer construction of dielectric stacks, with atomic and coating interface arrangements of crystalline and amorphous films may additionally be provided. The inorganic dielectric coating layer 16 provides a relatively close coefficient of thermal expansion (CTE) match to an SiC substrate so as to resist the thermal cycling typical of high temperature operations. The PLD process facilitates a robust coating and the engineered material allows, in one non-limiting embodiment, 3 microns of the inorganic dielectric coating layer 16 to store approximately 1000V.

The PLD process facilitates deposition of the inorganic dielectric coating layer 16 that can provide a flat dielectric constant at approximately 300° C. and the ability to place the inorganic dielectric coating layer 16 in various spaces so as to minimize wasted space. It should be understood that the PLD process facilitates deposition of the inorganic dielectric coating layer 16 on various surfaces inclusive of flat and curves surfaces.

Some factors which may affect the quality of the capacitor include the substrate surface smoothness, the smoothness of the oxide layer, and the thickness and surface area of the inorganic dielectric coating layer 16. A relatively thicker inorganic dielectric coating layer 16 provides a higher breakdown voltage but may facilitate cracks. A relatively larger electrode surface area tends to have more defects and therefore decrease breakdown voltage while a relatively smaller surface area tends to have a higher capacitor density and a higher breakdown voltage.

During development of the passive electrical component of the present disclosure, various material test coupons were evaluated. The operational capabilities of the capacitor are further defined from the following examples.

Referring to FIG. 2A, coupon testing proof of concept has show that the size of the capacitor 12 compared to current state-of-the art technology results in an approximately twenty times reduction in size and mass for the same voltage rating. Each coupon includes a multiple of capacitor areas C (FIG. 2B) with top contacts manufactured of aluminum for evaluation. FIGS. 3A-3N illustrates particular coupons with an average capacitance/breakdown voltage for each capacitor area C on the coupon. The test results provide a capacitance per area based in part on the material combination of the inorganic dielectric coating layer 16 (FIG. 4).

Referring to FIG. 5, another passive electrical component 10B is illustrated as an inductor 20. Capacitors are to electric fields what inductors are to magnetic fields. The inductor 20 includes a multiple of conductor layers 22, a multiple of high permeability layers 24 and an inorganic dielectric coating layer 26 between each conductor layer 22 and high permeability layer 24. The inductor 20 may include a multiple of layers, here illustrated with two conductor layers 22 and two high permeability layers 24. The multiple of conductor layers 22 and high permeability layers 24 may be built up upon the substrate 18 as a series of layers. The inductor 20 may be rectilinear in cross-section or of other cross-sectional shapes such as round (FIG. 6) which are built up about a wire or other solid.

The inductor 20 may be formed on a substrate 18. The substrate 18 may be a conductive substrate such as aluminum or a non-conductive substrate deposited with a conductive layer such as silicon carbide (SiC) layered with aluminum or other material.

The conductor layers 22 may be formed of, for example, aluminum, nickel, copper, gold or other conductive inorganic material or combination of materials.

The high permeability layers 24 may be manufactured of a permalloy material which is typically a nickel iron magnetic alloy. The permalloy material, in one non-limiting embodiment, includes an alloy with about 20% iron and 80% nickel content. The high permeability layer 24 has a relatively high magnetic permeability, low coercivity, near zero magnetostriction, and significant anisotropic magnetoresistance.

The inorganic dielectric coating layer 26 may be formed by the PLD process as previously described to separate the current flow through each conductor layer 22 and each high permeability layers 24 which travel in opposite directions.

System benefits of the high temperature passive electrical components disclosed herein include reduced weight and robust designs. The combination of high temperature electronic devices with high temperature passive electrical components provide effective operations in temperatures of up to 300° C. with relatively smaller, lighter heat sinks and/or the elimination of active cooling systems.

Although an inductor and capacitor are disclosed as passive electrical components, it should be understood that other passive electrical components such as resistors, strain gauges and others may be manufactured as disclosed herein. The inductor and capacitor may be deposited on the same substrate in various combinations to form power dense filters for power applications and general extreme environment electronic systems.

Referring to FIG. 7, another passive electrical component 10C is illustrated as a resistor 30 formed on a substrate 18. The substrate 18 may be manufactured of a non-conductive material such as Alumina or a conductive material with a non-conductive layer formed by the PLD process as previously described. Each conductive contact 32 and a resistive element 34 may also be formed by the PLD process. In one non-limiting embodiment, the resistor element 34 may include a mix of dielectric and conductive particles within an inorganic material of a resistive nature.

Referring to FIG. 8, passive electrical components 10 may be deposited directly upon a substrate which defines a module 40 for other electrical components. The other electrical components may be mounted within the module 40 in electrical communication with the passive electrical components 10 so as to provide a compact system such as the aforementioned portable/emergency power generators and aerospace power units. It should be understood that the passive electrical components 10 may alternatively be deposited on other substrates which provide other mechanical or electrical functionality.

It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom.

The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. 

1. A capacitor comprising: a first conductor layer; a dielectric layer laser applied to the first conductor layer; and a second conductor layer laser applied to the dielectric layer.
 2. A resistor comprising: a dielectric layer; a resistive layer laser applied to the dielectric layer; and a first conductor and a second conductor contacting the resistive layer, wherein the first conductor is not directly connected to the second conductor.
 3. An inductor comprising: a dielectric layer; a permeable layer laser applied to the dielectric layer; and a first conductor and a second conductor contacting the permeable layer, wherein the first conductor is not directly connected to the second conductor. 